Long-range electrostatic interactions significantly modulate the affinity of dynein for microtubules.
Long-range electrostatic interactions significantly modulate the affinity of dynein for microtubules.
复制标题
长程静电相互作用显著调节动力蛋白对微管的亲和力。
DOI：
10.1016/j.bpj.2022.03.029
复制
发表时间：
2022-05-03
影响因子：
3.4
通讯作者：
Alper JD
中科院分区：
文献类型：
--
作者：
Pabbathi A;Coleman L;Godar S;Paul A;Garlapati A;Spencer M;Eller J;Alper JD
微管负端定向运动蛋白的动力蛋白家族驱动真核细胞中的多种功能，包括细胞分裂、细胞内运输和鞭毛跳动。运动蛋白持续性表征了运动在与细丝分离之前行走的距离，取决于其微管结合域 (MTBD) 和微管之间的相互作用。动力蛋白的 MTBD 会在高结合亲和力状态和低结合亲和力状态之间切换。重要的结构和功能数据表明，MTBD 内以及 MTBD 与微管之间的特定盐桥控制着这些亲和状态的转变。然而，最近的计算工作表明，MTBD 和微管之间的非特异性、长程静电相互作用也可能在动力蛋白的持续合成过程中发挥重要作用。为了研究这一假设，我们将远离动力蛋白 MTBD 微管结合界面的带负电荷的氨基酸突变为中性残基，并使用微型热泳和光镊测量结合亲和力。我们发现突变的 MTBD 对微管的结合亲和力显着增加。此外，我们发现溶液中自由离子的电荷筛选对 MTBD 与微管的结合和解除结合率有不同的影响。总之，这些结果证明了长程静电相互作用在调节动力蛋白-微管亲和力中的重要作用。此外，这些结果还提供了对具有各种加工能力的分子马达之间的生物物理差异和更普遍的蛋白质-蛋白质相互作用之间潜在的生物物理差异的原理的深入了解。
The dynein family of microtubule minus-end-directed motor proteins drives diverse functions in eukaryotic cells, including cell division, intracellular transport, and flagellar beating. Motor protein processivity, which characterizes how far a motor walks before detaching from its filament, depends on the interaction between its microtubule-binding domain (MTBD) and the microtubule. Dynein’s MTBD switches between high- and low-binding affinity states as it steps. Significant structural and functional data show that specific salt bridges within the MTBD and between the MTBD and the microtubule govern these affinity state shifts. However, recent computational work suggests that nonspecific, long-range electrostatic interactions between the MTBD and the microtubule may also play an important role in the processivity of dynein. To investigate this hypothesis, we mutated negatively charged amino acids remote from the dynein MTBD-microtubule-binding interface to neutral residues and measured the binding affinity using microscale thermophoresis and optical tweezers. We found a significant increase in the binding affinity of the mutated MTBDs for microtubules. Furthermore, we found that charge screening by free ions in solution differentially affected the binding and unbinding rates of MTBDs to microtubules. Together, these results demonstrate a significant role for long-range electrostatic interactions in regulating dynein-microtubule affinity. Moreover, these results provide insight into the principles that potentially underlie the biophysical differences between molecular motors with various processivities and protein-protein interactions more generally.
登录
查看更多内容
影响因子：
16.8
作者：
通讯作者：
--
DOI：
10.1126/science.1164424
发表时间：
2008-12-12
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Carter AP;Garbarino JE;Wilson-Kubalek EM;Shipley WE;Cho C;Milligan RA;Vale RD;Gibbons IR
通讯作者：
Gibbons IR
影响因子：
9.9
作者：
Harms, M. B.;Ori-McKenney, K. M.;Baloh, R. H.
通讯作者：
Baloh, R. H.
DOI：
10.1007/978-1-61779-252-6_2
发表时间：
2011-01-01
期刊：
MICROTUBE DYNAMICS: METHODS AND PROTOCOLS
影响因子：
--
作者：
Gell, Christopher;Friel, Claire T.;Howard, Jonathon
通讯作者：
Howard, Jonathon
影响因子：
4.8
作者：
Gibbons, IR;Garbarino, JE;Carter, AP
通讯作者：
Carter, AP